bài1.Hoàn thành các câu sau

21. "Stop talking, Joe," the teacher said.

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22. "Be patient," she said to him.

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23. "Go to your room," her father said to her.

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24. "Hurry up," she said to us.

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25. "Give me the key," he told her.

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26. "Play it again, Sam," she said.

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27. "Sit down, Caron" he said.

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28. "Fill in the form, Sir," the receptionist said.

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29. "Take off your shoes," she told us.

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30. "Mind your own business," she told him

Baif2.Giải hệ phương trình

1.\(\dfrac{3}{x+1}-2y=-1\)

2.\(\dfrac{5}{x+1}+3y=11\)

Bài1

A=\(\dfrac{\sqrt{x}}{\sqrt{x}+3}\) và B=\(\dfrac{2\sqrt{x}}{\sqrt{x}-3}-\dfrac{3x+9}{x-9}vớix\ge0;x\ne9\)

1)Tính giá trị biểu thức A khi x=16

2)Chứng minh A+B=\(\dfrac{3}{\sqrt{x+3}}\)

Baif1.Tìm x để căn có nghĩa

a)\(\sqrt{4x^2-16}\)

b)\(\sqrt{9x^2-25}\)